Some useful organic compounds are known to be produced by adding a variety of compounds to an unsaturated compound having, for example, a carbon—carbon double bond or a heteroatom-containing compound. For example, when an active methylene compound such as a malonic diester is allowed to react with an olefin having an electron attracting group such as acrylonitrile in the presence of a base, a carbon—carbon bond is formed by a nucleophilic addition reaction to yield an adduct (Michael addition reaction). When two carbonyl compounds are treated in the presence of an acid or a base, one carbonyl compound is nucleophilically added to the other carbonyl compound and a carbon—carbon bond is formed to yield an aldol condensate.
However, a reaction is generally performed in the presence of an acid or a base according to these processes, and these processes cannot be applied to compounds having substituents that are unstable to acids or bases. According to these processes, for example, a hydroxymethyl group, an alkoxymethyl group, an acyl group, or a tertiary carbon atom cannot be directly bonded to a carbon atom of an unsaturated bond of an unsaturated compound or to a methine carbon atom of a bridged cyclic compound.
Addition reactions to carbon—carbon double bonds and coupling reactions to form carbon—carbon bonds through radical mechanism are also known. However, there is significantly no process for efficiently obtaining addition or substitution reaction products or oxidized products thereof, for example, with molecular oxygen under mild conditions.
Separately, some processes are known as production processes of hydroxy-γ-butyrolactone derivatives. For example, European Unexamined Patent Application Publication No. 2103686 discloses a process for synthetically obtaining pantolactone by allowing glyoxylic acid to react with isobutylene. Japanese Unexamined Patent Application Publication No. 61-282373 discloses a process also for synthetically obtaining pantolactone, by allowing glyoxylic hydrate to react with t-butyl alcohol. Tetrahedron, 933 (1979) discloses a process for synthetically obtaining pantolactone. This process includes the steps of hydrolyzing 4-hydroxy-2-methyl-5,5,5-trichloro-1-pentene to yield 2-hydroxy-4-methyl-4-pentenoic acid, and cyclizing this compound in the presence of hydrochloric acid. In addition, The Chemical Society of Japan, Spring Annual Meeting, Lecture Proceedings II, pp. 1015 (1998) reports that light irradiation to a mixture solution containing an α-acetoxy-α, β-unsaturated carboxylic ester and 2-propanol yields a corresponding α-acetoxy-γ,γ-dimethyl-γ-butyrolactone derivative. However, each of these processes employs a material that is not easily available, or requires special conditions for the reaction.
Of the butyrolactone derivatives, the following derivatives are not known: (1) spiro-type γ-butyrolactone derivatives each having a hydroxyl group at the α-position and a non-aromatic carbon ring bonded to the γ-position, (2) γ-butyrolactone derivatives each having a hydroxyl group at the α-position, a haloalkyl group, a substituted oxycarbonyl group, a cyano group, or an aryl group at the β-position, and a hydrogen atom, a hydrocarbon group or a heterocyclic group bonded to the γ-position, (3) γ-butyrolactone derivatives each having a hydroxyl group at the α-position, and a hydrogen atom and a group selected from hydrocarbon groups and heterocyclic groups bonded to the γ-position, and (4) α-hydroxy-γ-butyrolactone derivatives each having a bridged cyclic hydrocarbon group bonded to the γ-position, and (meth)acryloyl derivatives thereof. In addition, substantially no process can easily and efficiently produce γ-butyrolactone derivatives each having a hydroxyl group at the β-position.
Separately, a lithography technique is used for the formation of fine patterns of semiconductor integrated circuits. The lithography technique includes the steps of covering the substrate having a thin film formed thereon (work) with a resist, subjecting the work to selective exposure to yield a latent image of a target pattern, subjecting the work to developing to form a patterned resist, dry-etching the work using the pattern as a mask, and then removing the resist to yield the target pattern. In this lithography technique, g-ray, 1-ray, and other ultraviolet rays are used as light sources. However, with an increasing fineness of patterns, far ultraviolet rays, vacuum ultraviolet rays, excimer laser beams, electron beams, x-rays and other rays having a shorter wavelength are employed as the light sources.
To form fine patterns using such a short-wavelength light source (e.g., ArF excimer laser), the resist used must have a satisfactory transparency at the wavelength of the light source, have a good adhesion to the substrate, be resistance to dry etching, and be satisfactorily soluble in a developer in development. As such resist materials, polymers of polymerizable monomers each having a bridged ring or a lactone ring have receive attention in recent years.
For example, Japanese Unexamined Patent Application Publication No. 9-73173 proposes a resist material as a photoresist suitable for a short-wavelength light source. This resist material includes a polymer and an acid generator, and the polymer comprises a structural unit which is protected by adamantane or another alicyclic hydrocarbon group and is to be eliminated by action of an acid to make the polymer soluble in alkalis. The resist material includes no aromatic ring, is thus transparent to the ArF excimer laser light or the like, and is satisfactorily resistant to dry etching. However, the resist material may not be rapidly dissolved in a developer, because the protective moiety is not sufficiently eliminated by an acid generated through light irradiation. Accordingly, the resist material is still insufficient in definition (photosensitivity, sensitivity), and is still insufficient in adhesion to a substrate.